A confocal Raman spectroscopy was developed with 830 nm laser excitation. High Raman spectra of various morphological structures in arterial wall such as elastic lamina, collagen fibers, adventitial fat, cholesterol crystals, foam cells and calcium mineralization. The objective the present estimate quantitative biochemical composition of each of the morphological structures present in tissues. We used a least square minimization routine to model spectra of morphological structure in terms of nine biochemical such as collagen, elastin, triolein, cholesterol, cholesterol linoleate, phosphatidyl choline, b-carotene, calcium hydroxy apatite, and calcium carbonate. Near perfect fit were obtained for each morphological structure studied and chemical composition was determined. Comparison of these results provided detailed information about intra and inter structural chemical variations at different stages of atherosclerosis.